1. Field of the Invention
This invention relates generally to a substrate upon which integrated circuit components are mounted and, more particularly, to a substrate that reduces electromagnetic emissions and associated electromagnetic interference problems.
2. Description of the Related Art
In the field of electronics, various integrated circuit components, such as microprocessors, are commonly mounted on a substrate. This substrate is typically comprised of ground layers, signal layers, and power layers. The signal layer contains traces that allow the transmission of various signals between the various integrated circuit components positioned on the substrate.
It is well known in the art that signals traveling within these traces can produce electromagnetic emissions, i.e., radiated electrical fields. Electromagnetic interference ("EMI") can cause several problems, such as malfunctions of nearby electrical devices and interference or degradation of signals traveling along other traces. EMI problems have resulted in the Federal Communications Commission adopting guidelines for maximum allowable levels of electromagnetic emissions in various electronic devices.
It is also well known that faster signal speeds lead to more EMI problems. With the emphasis on increased operating speeds of today's integrated circuit devices, EMI problems also increase.